This study aims to address fundamental, yet unresolved, issues in the disease progression of multiple sclerosis. Dr. Grossman, the principle investigator, has requested GCRC support for admitting patients who cannot undergo all testing in a single day due to their severe disabilities. Therefore, even though 44 patients hae been enrolled in the study to date, only six patients have needed to be admitted to the GCRC. The competitive application for the study extension has recently been funded and the total number of patients expected to be enrolled in the study has now increased to 65. The updated completion date is now October 2004.